The objective of this proposal is the incorporation of family study methods into selected areas of research on indicators for treatment response. The proposed research is a collaborative effort between the principal investigator and several current research projects at WPIC. The primary emphasis is on depression. Serotonin uptake rates by platelets and EEG sleep parameters may be discriminators for potential response to drug treatments, such as amitriptyline. This project proposes to study other family members to determine whether familiality exists for these assessments. The final study hopes to make a major contribution to the study of genetic- environment interactions of vulnerabilities. This study is a prototype for proposed future research on depression by the investigator. In collaboration with a treatment study of schizophrenics, attentional tests (Continuous Performance Test and Span-of-Apprehension Test) will be given to family members. Family psychosocial environment will be assessed by the Camberwell Family Inventory (Expressed Emotion), Family Distress Scale, and Family Environment Scale. The joint determination allows testing of models of interaction.